North Korea has focused on enlarging its nuclear and missile arsenals in recent years. The launch from North Korea's eastern coastal Wonsan area was detected about 5pm, South Korea's Joint Chiefs of Staff said on Thursday, explaining that South Korea's military has bolstered its surveillance posture and is closely co-ordinating with the US and Japan. The ballistic missile launch was North Korea's first since late June, when it tested a tactical ballistic missile with a "special mission" warhead and other weapons. After years of prioritising ballistic missile development, Kim has increasingly turned his focus to naval capabilities, including the construction of a nuclear-powered submarine. North Korea has supplied conventional weapons and troops to Russia to support its war against Ukraine.